1. Field of the Invention
The invention relates to a method and an apparatus for compactly folding an airbag, or gas sack, of an airbag apparatus in vehicles, particularly motor vehicles.
2. Description of the Prior Art
In a known method of folding an airbag of an airbag apparatus (DE 44 40 845 A1), the folding of the flat airbag is to take place substantially by a relative rotation between at least two wall sections. For this purpose, the flattened and spread out airbag is clamped at a radially outward portion by clamping devices, whereupon the clamping module is rotated relative to the central holding device. Through this rotary movement, the outer diameter of the airbag is reduced, necessitating the radially inward movement of the clamping devices. Due to the superimposing of the rotary movement of a clamping location relative to the central inward opening with the translatory radially inward movement, the clamping locations of the airbag and the clamping devices move on a spiral track towards the inlet opening. During this movement, the wall of the airbag is arranged in a coil-like manner around the inlet opening. In the fully turned in state of the airbag its entire wall is arranged generally in a bead-like or tire-like manner around the inlet opening, with the clamping locations coming to lie at the outer surface of the folded airbag. The rotary movement is continued until the desired folding packing density is achieved.
A disadvantage of this known method is that the folding of the two sheets of the airbag, which takes place during winding, proceeds in a relatively uncontrolled manner so that the shape of the finally obtained compact airbag package is not precisely reproducible.